Regulatory Matters (Regulatory Matters Narrative - Duke Energy Indiana) (Details) - IURC - Duke Energy Indiana $ in Millions	Feb. 13, 2025 USD ($) MW	Feb. 07, 2025 USD ($)	Feb. 03, 2025 USD ($)	Apr. 30, 2024 USD ($)	Sep. 20, 2023	Jun. 15, 2022 USD ($)
Indiana Coal Ash Recovery
Public Utilities, General Disclosures [Line Items]
Interest rate on refunds (as a percent)					4.71%
TDSIG 2.0
Public Utilities, General Disclosures [Line Items]
Future investment in infrastructure						$ 2,000
2024 Indiana Rate Case
Public Utilities, General Disclosures [Line Items]
Future investment in infrastructure				$ 1,600
Approved return on equity percentage (as a percent)			9.75%
Equity ratio (as a percent)			53.00%
Approved rate increase (decrease), amount		$ 385	$ 296
Cayuga Combined Cycle CPCN, Gas-Fired
Public Utilities, General Disclosures [Line Items]
New combustion turbines (in megawatts) \| MW	1,476
Cayuga Combined Cycle CPCN, Coal-Fired
Public Utilities, General Disclosures [Line Items]
New combustion turbines (in megawatts) \| MW	1,005
Cayuga Combined Cycle CPCN
Public Utilities, General Disclosures [Line Items]
New combustion turbines (in megawatts) \| MW	471
Estimated cost of facilities	$ 3,300
Requested rate increase, percentage, net of tax	5.40%